Apparatus for the ultra-sonic welding of sealing seams

Abstract

The description relates to an apparatus for the ultrasonic welding of sealing seams on packages for fluid media. The apparatus comprises a sonotrode and an anvil (7) which is situated opposite the front end face of the sonotrode. Both sonotrode and also anvil (7) are adapted for movement on predetermined paths. So that the bearings of the machine as a whole are not adversely affected by the vibrations of the sonotrode and thus also of the anvil and in order to guarantee good hygiene qualities, it is according to the invention envisaged that the anvil which is of solid construction should be traversed axially by at least one inner bore (12, 13, 14) in which, for neutralizing vibrations, a shaft (9; 10, 11) is disposed contactlessly via elastic flexible ring parts (16) so that an annular gap is formed, the outside diameter of the shaft being less than the inside diameter of the inner bore (12, 13, 14) and in that the outside diameter of the elastic ring part (16) is greater than the inside diameter of the inner bore.

I claim: 
     
       1. An apparatus for the ultrasonic welding of sealing seams, particularly on the doubled cardboard strip (2) of a package (1) for fluid media, the apparatus comprising a sonotrode (5) and, opposite its front end face (3), an anvil (7), both of which can be moved on predetermined paths, characterised in that the solidly constructed anvil (7, 7') is axially traversed by ay least one inner bore (12, 13, 14) in which, in order to neutralized vibrations, a shaft (9; 10, 11) is disposed in contactless manner via elastic flexible ring parts (16), forming an annular gap (15), the outside diameter of the shaft being smaller than the inside diameter of the inner bore (12, 13, 14) and in that the outside diameter of the elastic ring part (16) is greater than the inside diameter of the inner bore (12 to 14). 
     
     
       2. An apparatus according to claim 1, characterized in that in the outer surface of the shaft (9, 10, 11) in its axial direction there are a number of grooves (17) spaced apart from one another by the distance (a) and which at least partially accommodate the ring parts (16). 
     
     
       3. An apparatus according to claim 1 or 2, characterized in that the ring parts (16) are O-rings which preferably have different degrees of stiffness "C". 
     
     
       4. An apparatus according to any one of claims 1 to 2, characterized in that the anvil (7, 7') is traversed axially and in a parallel arrangement by three inner bores (12, 13, 14) for holding two supporting shafts (10, 11) and a carrier shaft (9) mounted on the machine as a whole, and in that the anvil is preferably constructed from stainless steel. 
     
     
       5. A apparatus according to any one of claims 1 to 2, characterized in that the carrier shaft (9) is mounted at its ends (21) in supports (18) rigid with the machine, held by fitting members (20) which engage around the ends (21). 
     
     
       6. An apparatus according to claim 5, characterized in that between shoulder (27) of the fittinq member (20) and end face (25) of the anvil (7) there is an O-ring of flexible elastic material and which is adapted to be clamped in place by at least one screw (22) which projects axially into the end (21) of the carrier shaft (9) and through fitting member (19). 
     
     
       7. An apparatus according to any one of claims 1 to 2, characterized in that on the carrier shaft (9) and the at least one supporting shaft (10, 11) extending parallel therewith are at least two anvils (7,7') which are disposed axially serially and are supported by shoulders (23, 23') formed on the shafts (9, 10, 11) at spacing (d) and in that O-rings (16) are provided between shoulder (23, 23') and anvil (7, 7'). 
     
     
       8. An apparatus according to claim 3, characterized in that the anvil (7, 7') is traversed axially and in a parallel arrangement by three inner bores (12, 13, 14) for holding two supporting shafts (10, 11) and a carrier shaft (9) mounted on the machine as a whole, and in that the anvil is preferably constructed from stainless steel. 
     
     
       9. An apparatus according to claim 3, characterized in that the carrier shaft (9) is mounted at its ends (21) in supports (18) rigid with the machine held by fitting members (20) which engage around the ends (21). 
     
     
       10. An apparatus according to claim 4, characterized in that the carrier shaft (9) is mounted at its ends (21) in supports (18) rigid with the machine, held by fitting members (20) which engage around the ends (21). 
     
     
       11. An apparatus according to claim 3, characterized in that on the carrier shaft (9) and the at least one supporting shaft (10, 11) extending parallel therewith are at least two anvils (7, 7') which are disposed axially serially and are supported by shoulders (23, 23') formed on the shafts (9, 10, 11) at spacing (d) and in that O-rings (16) are provided between shoulder (23, 23') and anvil 7, 7'). 
     
     
       12. An apparatus according to claim 4, characterized in that on the carrier shaft (9) and the at least one supporting shaft (10, 11) extending parallel therewith are at least two anvils (7, 7') which are disposed axially serially and are supported by shoulders (23, 23') formed on the shafts (9, 10, 11) at spacing (d) and in that O-rings (16) are provided between shoulder (23, 23') and anvil 7, 7'). 
     
     
       13. An apparatus according to claim 5, characterized in that on the carrier shaft (9) and the at least one supporting shaft (10, 11) extending parallel therewith are at least two anvils (7, 7'), which are disposed axially serially and are supported by shoulders (23, 23') formed on the shafts (9, 10, 11) at spacing (d) and in that O-rings (16) are provided between shoulder (23, 23') and anvil 7, 7'). 
     
     
       14. An apparatus according to claim 6, characterized in that on the carrier shaft (9) and the at least one supporting shaft (10, 11) extending parallel therewith are at least two anvils (7, 7') which are disposed axially serially and are supported by shoulders (23, 23') formed on the shafts (9, 10, 11) at spacing (d) and in that O-rings (16) are provided between shoulder (23, 23') and anvil (7, 7').